1. Field of the Invention
This invention relates to rocker assemblies for attachment to stationary chairs and more particularly to a simple low-cost rocker assembly for use on folding chairs of the type commonly referred to as "lawn chairs".
2. Description of the Prior Art
Many attempts have been made over the years to develop a simple low-cost rocker assembly for converting a stationary chair into a rocker. Early developments in this art are exemplified by U.S. Pat. No. 1,231,151 issued to W. H. Gerrard, Jr. on June 26, 1917, and U.S. Pat. No. 1,295,382 issued on Feb. 25, 1919 to M. J. Stelzer. In these two prior art patents, the bottom ends of four depending legs of conventional chairs are received in especially configured socket-like fixtures that are carried on a spaced pair of arcuately shaped rockers.
U.S. Pat. No. 2,662,581 issued to L. Gottfried on Dec. 15, 1953 shows several rocker attachment configurations for use on various types of chairs. Of particular interest is the embodiment which is adapted to attach to a folding lawn chair of the type having U-shaped front and rear ground engaging members. The rocker attachment includes a spaced pair of arcuate rockers which are interconnected by a pair of spaced U-shaped in cross section channel members fixedly carried on the top of the rockers. The channel members are laid on their sides so as to be open on the sides which face each other. The bottom segments of the chair's ground engaging members are inserted into the channels of the rocker attachment during unfolding of the chairs, and are secured therein by spring bolts.
U.S. Pat. No. 4,079,991 issued on Mar. 21, 1978 to Harris discloses an especially configured pair of arcuate rocker devices which may be attached to either conventional chairs or to those referred to as folding lawn chairs. In the case of the lawn chairs, the U-shaped ground engaging members may either be tied to the arcuate rockers or may be snapped into special grooves formed transversely in the rockers.
In general, all the above discussed prior art devices are relatively complex and expensive to fabricate and this alone has contributed significantly to the lack of widespread commercial acceptance. More specifically, the structure disclosed in the Gottfried Patent cannot be adapted for use on different size chairs due to the fixed attachment of the channels on the rockers, and also attachment of the lawn chair can be an awkward task. The Harris Patent requires that the special rockers be fabricated of flexible and compressible materials such as plastic, and the cost of fabricating such special rockers is prohibitive in all but extremely high production.
Therefore, a need exists for a new and improved rocker attachment for converting a stationary folding lawn chair into a rocker, with this attachment being simple to use, inexpensive to manufacture, and otherwise overcoming some of the drawbacks and shortcomings of the prior art.